Deuteron activation cross section measurements at the NPI cyclotron

Transcription

1 Nuclear Physics Institute Řež EAF 2011 Deuteron activation cross section measurements at the NPI cyclotron E. Šimečková, P. Bém, M. Honusek, J. Mrázek, M. Štefánik, L. Závorka Nuclear Physics Institute AS CR, CZ Řež, Czech Republic M. Avrigeanu, V. Avrigeanu Horia Hulubei National Institute for Physics and Nuclear Engineering, P.O. Box MG-6, Bucharest-Magurele, Romania U. Fischer, S.P. Simakov Karlsruhe Institute of Technology, KIT INR, D Eggenstein-Leopoldshafen Germany Workshop on Activation Data EAF 2011, Prague, 1-3 June

2 Motivation The proton and deuteron induced activation reactions have a great interest for the assessment of induced radioactivities in the accelerator components, targets and beam stoppers as well as isotope production for medicine. The IFMIF facility needs such a data for estimation of the potential radiation hazards from the accelerating cavities and beam transport elements (Al, Fe, Cr, Cu, Nb) and metal and gaseous impurities of the Li loop (Be, C, O, N, Na, K, S, Ca, Fe, Cr, Ni). The cross sections are needed in the energy range from the threshold (2-10 MeV) up to 40 MeV both for deuterons and protons. The description of deuteron-nucleus interaction represents an important tests for both the quality of reaction mechanism models and evaluation of nuclear data request especially for fusion reactor technology. 2

3 FISPACT-2007 FISPACT is the inventory code included in the European Activation System (EASY), has been developed for neutron-, deuteron-, and proton-induced activation calculations for materials in fusion devices, has been adopted by the ITER project as the reference activation code, uses external libraries (EAF-libraries) of reaction cross sections and decay data for all relevat nuclides to calculate an inventory of nuclides produced as a result of the irradiation of a starting material with a flux of neutrons (from FISPACT-2007 version also with a charged particles). The deuteron cross section data are recorded in VITAMIN-J+ (211) standard group structure (up to 55 MeV). 3

4 U-120M variable energy cyclotron of NPI Possible shift in energy 2 % Possible energy spread 2 % The energy is determined with the calculation of trajectory and position of cyclotron extraction foil. This correctness of energy determination was tested using the scattering of extracted beam on CH2 radiator. E d = 20.4 MeV Target station NG2 target station - negative ion mode. The cross-sections for deuteron reactions on Al, Cu, Fe, Nb and Co were measured by the stackedfoil technique 4

5 Irradiation chamber Faraday cup Full beam stop screen Faraday cup target DEUTERON BEAM During an irradiation, the beam current was recorded with the uncertainty of 5 % in a PC keeping time synchronization with the γ-ray spectrometry device. current measurement cooling current measurement 5

6 Irradiated samples The cross-sections for deuteron provoked reactions on Cu, Fe were measured by the stacked-foil technique and its absolute values were calculated from the measured induced activities. DEUTERON BEAM stacks of Cu (Fe) and Al foils placed by turns Al, Cu, Fe, Nb, Co purity 99.9 % (Goodfellow product) thickness Cu, Fe, Nb, Co 25 μm; Al -50 μm Cu-1 Cu-3 Cu-5 Cu-19 Cu-21 The foil were weighed to avoid relatively large uncertainties (15 %) in the foil thickness declared by producer (2 %). Al foils served for additional monitoring of beam current and for appropriate reduction of deuteron energy, as well. Energy attenuation, target density - SRIM

7 Gamma-spectroscopy The irradiation time varied from 5 to 60 min. with mean beam current from 0.1 μa to 0.4 μa The gamma-rays from the irradiated foils were measured repeatedly by two calibrated HPGe detectors of 23 and 50 % efficiency and of FWHM 1.8 kev at 1.3 MeV. Cooling time measurement up to 100 d. Experimental reaction rates were calculated from the specific activities et the end of irradiation corrected to decay during irradiation using total charge and foil characteristics as well. 7

8 d + Al activation experiment 27 Al(d,p) 28 Al Prague,Krakow, 1-3 June October 2010 EAF

9 d + Cu activation experiment T 1/2 = 2.52 h 65 Cu+d 65 Ni+2p T = 3.7 MeV T 1/2 = d 63 Cu - 69,2 % 65 Cu 30,8 % T 1/2 = m T 1/2 = 9.19 h 63 Cu+d 63 Zn+2n T = 6.6 MeV 65 Cu+d 63 Zn+4n T = 25.0 MeV T 1/2 = 5.12 m 65 Cu+d 66 Cu+p T = 0.0 MeV T 1/2 = 12.7 h β + decay β - decay 9

10 Dead time reduction HPGe detector Pb Cu foil Fe Fe Run Time Current C 335 s 0.24 μa D 300 s 0.36 μa 1 cm 1 mm 1 mm 152 Eu Attenuation: x x Calibration uncertainty - 3 % Isotop T 1/2 E γ [kev] 66 Cu 5.12 m Zn m Iγ [%]

11 d + Cu Prague, Prague, 1-3 June June 2011 EAF 2011 EAF

12 d + Fe activation experiment Fe foils purity 99.9 % (Goodfellow product) thickness - ~ 25μm Run Irradiation time Mean current 54 Fe 5.8 % 56 Fe 91.8 % A min 0.20 μa B min 0.24 μa 57 Fe 2.1 % 58 Fe.3 %

13 nat Fe(d,*) 56 Co Reaction Treshold [MeV] 54 Fe(d,γ) Fe(d,2n) Fe(d,3n) T 1/2 E γ [kev] I γ [%] d

14 nat Fe(d,*) 56 Mn Reaction Treshold [MeV] 56 Fe(d,2p) Fe(d,h+) Fe(d,α+) 0.0 T 1/2 E γ [kev] I γ [%] h

15 nat Fe(d,*) 54 Mn Reaction Treshold [MeV] 54 Fe(d,2p) Fe(d,α+) Fe(d,nα+) 2.06 T 1/2 E γ [kev] I γ [%] d Prague, 1-3 June 2011 EAF 2011

16 nat Fe(d,*) 52 Mn Reaction Treshold [MeV] 54Fe(d,α+) Fe(d,2nα+) T 1/2 = d E γ [MeV] I γ [%]

17 nat Fe(d,*) 52m Mn T 1/2 = 21.1 min E γ [MeV] I γ [%]

18 nat Fe(d,*) 55 Co Reaction Treshold [MeV] 54 Fe(d,n) Fe(d,3n) T 1/2 = h E γ [MeV] I γ [%]

19 nat Fe(d,*) 57 Co Reaction Treshold [MeV] 56 Fe(d,n) Fe(d,2n) Fe(d,3n) T 1/2 E γ [kev] I γ [%] d

20 nat Fe(d,*) 58(m+g) Co 58m Co 58 Co 24.9 kev 9.04 h d Eγ [kev] Iγ [%]

21 nat Fe(d,*) 58m Co T 1/2 = 9.04 h λ g A g = A 0 m (e-λ m t -e -λ g t ) + A 0 g e-λ g t λ g - λ m Eγ [kev] Iγ [%] 24.9 kev

22 nat Fe(d,*) 58g Co

23 nat Fe(d,*) 59 Fe Reaction Treshold [MeV] 58 Fe(d,p) 0.0 T 1/2 E γ [kev] I γ [%] d

24 nat Fe(d,*) 51 Cr Reaction Treshold [MeV] 54 Fe(d,pα+) Fe(d,tα+) T 1/2 E γ [kev] I γ [%] d

25 d + Nb activation experiment Nb foils purity 99.9 % (Goodfellow product) thickness - ~ 25μm 93 Nb(d,p) 94m Nb E [MeV] σ [mb] (28) 51.9 (58) T 1/2 E γ [kev] I γ [%] min Initial energy MeV Total charge µc Irradiation time 43.3 min Mean current µa F.Tarkanyi et al., Nucl. Instrum. and Meth. B 255 (2007) 297

26 93 Nb(d,2n) 93m Mo Nb(d,2n) 93m Mo Cross section [mb] TAR 07 present work T 1/2 E γ [kev] I γ [%] 6.85 h Deuteron energy [MeV]

27 93 Nb(d,2n) 92m Nb Nb(d,t+) 92m Nb Cross section [mb] Deuteron energy [MeV] TAR 07 present work T 1/2 E γ [kev] I γ [%] d

28 93 Nb(d,pα+) 92m Y 93 Nb(d,pα+) 90m Y Cross section [mb] 10-1 T 1/2 E γ [kev] I γ [%] 3.19 h Deuteron energy [MeV] TAR 07 present work

29 d + Co activation experiment 58 Co foils purity 99.9 % (Goodfellow product) thickness - ~ 25μm Initial energy Total charge Irradiation time Mean current MeV 349.5μC 66.7 min μa R.Michel, M.Galas, Applied Radiation and Isotopes, Vol.34 (1983) 1325 F.Ditroi, F.Tarkanyi et al., Nucl. Inst. end Meth., B 268 (2010) 2571

30 59 Co(d,2p) 59 Fe Co(d,2p) 59 Fe T 1/2 E γ [kev] I γ [%] d Cross section [mb] MICH 83 DIT 10 present work R.Michel, M.Galas, Applied Radiation and Isotopes, Vol.34 (1983) 1325 F.Ditroi, F.Tarkanyi et al., Nucl. Inst. end Meth., B 268 (2010) Deuteron energy [MeV]

31 59 Co(d,pα+) 56 Mn Co(d,pα+) 56 Mn Cross section [mb] MICH 83 present work Deuteron energy [MeV] T 1/2 E γ [kev] I γ [%] h

32 59 Co(d,nt+) 57 Co 59 Co(d,nt+) 57 Co 10 0 Cross section [mb] MICH 83 DIT 10 present work T 1/2 E γ [kev] I γ [%] d Deuteron energy [MeV]

33 59 Co(d,p) 60 Co 600 Cross section [mb] Co(d,p) 60 Co MICH 83 DIT 10 present work T 1/2 E γ [kev] I γ [%] y Deuteron energy [MeV]

34 59 Co(d,t+) 58(m+g) Co 58m Co 58 Co 24.9 kev 9.04 h d 59 Co(d,t+) 58m+g Co Eγ [kev] Iγ [%] Cross section [mb] MICH 83 DIT 10 present work Deuteron energy [MeV] Prague, 1-3 June 2011 EAF2011

35 59 Fe(d,t+) 58m Co T 1/2 = 9.04 h λ g A g = A 0 m (e-λ m t -e -λ g t ) + A 0 g e-λ g t λ g - λ m Co(d,t+) 58m Co Cross section [mb] Deuteron energy [MeV] present work Eγ [kev] Iγ [%] 24.9 kev April 2010 ND2010

36 Conclusion The cross-sections of (d,x) reactions induced by 20 MeV deuterons on stack of Al, Cu, Fe, Nb and Co foils were measured. Uncertainty: statistical and detector efficiency 3% - 6% possible shift in energy 2 % possible energy spread 2 % beam charge measurement 5 % foil thickness 2 % Resulting cross section data are in agreement with the major part of previous data, a few from those were determined for the first time An attempt to determine cross-sections for nat Fe(d,*) 58m Co, nat Fe(d,*) 58g Co and 59 Co(d,*) 58m Co separately was done. Present experimental results indicate necessity of further development of EAF deuteron database. Improvement of monitoring characteristics (initial energy, charge) under progress. The measurement with the beam energy extended up to 40 MeV will be performed on SPIRAL 2. Praque, 1-3 June 2011 EAF 2011